No abstract

In this article, we report the successful assembly of nanoparticles (NPs) from a water-soluble chitosan (CS) derivative (N-(2-hydroxyl)propyl-3-trimethyl ammonium chitosan chloride, HTCC) and zein via a low-energy phase separation method.

No abstract

Organic–inorganic hybrid molecular ferroelastics have gained widespread attention as a promising candidate for data storage, sensor, and mechanical switch applications. However, it remains a great challenge to construct new molecular ferroelastic materials. Based on the “quasi-spherical theory”, we designed and synthesized a new quasi-spherical cation [DMIE]+ ([DMIE]+ is dimethyl-isopropyl-ethyl-ammonium cation) to expect ferroelastic materials. Unfortunately, [DMIE]­[Cd­(SCN)3] (1) undergoes a structural phase transition from the space group P63 to P63/mmc, which is not among the 94 species of ferroelastic phase transitions as suggested by Aizu. Herein, by introducing electronegative halogen (F, Cl, or Br) atoms to the [DMIE]+ cation, the symmetry groups of the corresponding cadmium thiocyanate perovskites get efficiently lowered to orthorhombic Pbca to induce ferroelastic phase transitions with an Aizu notation of 6/mmmFmmm. The spontaneous strain value reduces from 0.0778 in a fluorinated product to 0.0428 in a brominated product. Accompanied by the introduction of halogen groups from F to Br, the phase transition temperature increases from 248.6 to 367.8 K. This work demonstrates that the strategy of combining a quasi-spherical molecule with specific electronegative groups provides an efficient way to offer molecular ferroelastic materials.

No abstract

Organic−inorganic hybrid perovskites are currently an active research topic in the field of energy and next-generation electronics. Their selectable organic and inorganic components provide infinite possibilities for designing functional materials with multiple applications. Herein, we present a new one-dimensional BaNiO 3 -like organic−inorganic hybrid perovskite (thiazolidinium)CdBr 3 (1), which displays a phase transition at 263 K and a switchable second harmonic generation (SHG) response. Intriguingly, 1 shows a pyroelectric coefficient p e of ∼0.6 μC•cm −2 •K −1 and a piezoelectric output voltage of ∼2.0 V for our fabricated piezoelectric generation device, indicating its great potential for pyroelectric sensors, self-powered low-voltage electronic devices, and energy harvesters. Moreover, the presence of a specific thioether donor enables 1 to appropriately adsorb Pd(II) ions, which can be monitored by the corresponding change in phase transition behavior, SHG signal, and pyroelectric response. This work provides a new insight to develop new multifunctional materials, demonstrating the feasibility of utilizing organic− inorganic hybrid perovskites to realize future self-powered low-voltage devices and energy harvesters.

Molecular ferroelectrics have gradually aroused great interest in both fundamental scientific researches and technological applications because of their easy processing, lightweight, and mechanical flexibility. Hybrid organic-inorganic perovskite ferroelectrics (HOIPFs), as a class of molecule-based ferroelectrics, have diverse functionalities owing to their unique structure and become a hot spot in molecular ferroelectrics research. Therefore, they are extremely attractive in the field of ferroelectric. However, it seems to be a lack of systematic review of their design, performance, and potential applications. Herein, we review the recent development of HOIPFs from lead-based, lead-free, metal-free perovskites and outline the versatility of these ferroelectrics, including piezoelectricity for mechanical energy harvesting and optoelectronic properties for photovoltaics and light detection. Furthermore, a perspective view of the challenges and future directions of HOIPFs is also highlighted.

In this work, biodegradable nanoparticles (NPs) were assembled with sodium carboxymethyl cellulose (CMC) and zein to produce zein–CMC NPs.